#include<bits/stdc++.h>
using namespace std;
int main(){
    int N;
    cin>>N;
    vector<double>vec(N);
    for(double &i:vec){
        cin>>i;
    }
    sort(vec.begin(),vec.end());
    if(N%2==1){
        cout << vec[N/2] << endl;
    }
    else{
        cout << (double)((vec[N/2]+vec[N/2-1])/2) << endl;
    }
}